Method And Apparatus For Positioning A Multiple Piece Prosthesis

ABSTRACT

A method and apparatus for positioning an implant system in anatomy is disclosed. The apparatus can include an alignment member operable to contact an implant portion, a bone, or other appropriate portion. The method can include using the apparatus to assist in positioning a single or multi-piece implant member. Also, a method of aligning a first implant position relative to another implant position is disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/444,270 filed on May 31, 2006. The disclosure of the aboveapplication is incorporated herein by reference.

FIELD

A method and apparatus for performing an orthopedic procedure,specifically a method and apparatus for performing an arthroplastyincluding preparing two portions of a bone.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

An anatomy, such as a human anatomy, includes various portions that areoperable to move relative to one another. A joint generally allows fortwo portions, such as bony portions, to move relative to one another.For example, a knee joint is generally formed between the femur and thetibia and also articulation of the femur and the tibia at a selectedlocation. For various reasons, such as disease, age, injury or the like,the various articulating regions may no longer be able to perform theanatomical action of the smooth and pain-free articulation. It may beselected, if possible, to replace the portions of the anatomy with aprosthesis. Prostheses, such as those generally known in the art, varywidely in their construction, method of implantation, and the like.

Generally, a total knee arthroplasty (TKA) requires a replacement of theentire articulation or condylar portion of the femur and the entirearticulation region of the tibia. Generally, a single element replaceseach of the articulating portions of the femur. Nevertheless, it may bedesirable to replace only selected portions of the femur, such as themedial and lateral condyles that articulate with the tibia. It may bedesirable to maintain the remaining portions of the femur for variouspurposes, such as bone retention, cartilage retention, or the like.Therefore, it may be desirable to provide a method and apparatus forpositioning and implanting a plurality of articulating elements toarticulate with a selected portion of the anatomy.

It can also be desirable to provide an implant system that allows forperforming more than a single cut or resection on a selected bone basedupon or aligned relative to a first cut or resection on a bone. Thesystem may allow for positioning a substantially single piece implantrelative to the cut bone surface once the one or more cuts are made.Therefore, a system that allows for forming multiple cuts on a singlebone aligned relative to a first cut may be desirable.

SUMMARY

A method and apparatus for positioning and implanting a prosthesisrelative to a joint is disclosed. The apparatus can be any appropriateapparatus that can allow for aligning a first portion of the anatomywith a second portion of the anatomy to allow for positioning theprosthesis relative to the anatomy. Generally, the various portions ofthe anatomy can be aligned for resection, such as aligning a firstresected portion relative to a second resected portion to achieve aresult. Alternatively, a first implant member can be aligned relative toa second implant member to achieve a selected result. This can allowvarious implant members to not be interconnected in a fixed manner,either during or after the implantation procedure. An implant, however,can be formed as a single piece.

According to various embodiments a system for positioning a prosthesisis disclosed. The system can include a first alignment portion and asecond alignment portion. An adjustment mechanism can be provided tointerconnect with at least one of the first alignment portion, thesecond alignment portion, or combinations thereof. Also, a manipulationmember can extend from at least one of the first alignment portion, thesecond alignment portion, or combinations thereof. At least one of thefirst alignment portion or the second alignment portion is adjustablerelative to the other of the first alignment portion or the secondalignment portion to assist in determining a position of the firstalignment portion to the second alignment portion.

According to various embodiments a method of positioning a prosthesismember on a single bone in a joint of an anatomy is disclosed. Themethod can include obtaining access to the joint. A first prosthesismember can be positioned on a first portion of the single bone and aposition of a resection on a second portion of the single bone can bedetermined or obtained. The resection on the second portion of thesingle bone and a second prosthesis member can be positioned on thesingle bone.

According to various embodiments a method of positioning a prosthesismember on a single bone in a joint in an anatomy is disclosed. Themethod can include obtaining access to the joint and performing a firstresection on a first portion of the single bone at a first location. Aposition of a second resection on a second portion of the single bonecan be obtained or determined and a second resection based upon theobtained position can be performed. A single piece prosthesis member ora multiple piece prosthesis assembly can be installed on the singlebone.

According to various embodiments a method of positioning a prosthesismember on a single bone in a joint in an anatomy is disclosed. Themethod can include obtaining access to the joint and performing a firstresection on a first portion of the single bone. A first prosthesismember can be positioned relative to the single bone near the firstportion. A position of a second resection on a second portion of thesingle bone can be determined based at least in part on a position ofthe first prosthesis member after it is positioned and the secondresection can be formed on the single bone.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andvarious examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1 is a perspective view of an alignment device according to variousembodiments;

FIG. 2 is a perspective view of an assembled alignment device accordingto various embodiments;

FIG. 3 is a perspective view of an implant system according to variousembodiments;

FIG. 4 is a perspective view of a portion of an anatomy;

FIG. 5 is a perspective view of an environmental view of an alignmentdevice in use according to various embodiments;

FIG. 6 is an environmental implanted view of a system of implantsaccording to various embodiments;

FIG. 7 is a perspective view of an environmental view of an alignmentdevice in use according to various embodiments;

FIG. 8 is a perspective view of an environmental view of an alignmentdevice in use according to various embodiments; and

FIG. 9 is a plan environmental view of a guide assembly according tovarious embodiments.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses.

With reference to FIGS. 1 and 2, an alignment or spacing instrument 10is illustrated. The spacing instrument 10 can include a spacer portion12 that extends from an end of a rod 14 that can be interconnected witha handle 16. Operable with the spacer portion 12, can be an adjustmentmechanism, the adjustment mechanism can include various modular spacers,such as a modular spacer 18 and a modular spacer 20. The modular spacers18, 20 can be interconnected or operable with the spacer portion 12 toachieve a selected spacing alignment.

The modular spacers can be provided in any appropriate number and size.For example, a plurality of spacers can include dimensions, such as aheight dimension, that varies by about 2 mm a piece. The various spacerscan be positioned in the connection ports 22, 24 of the spacer portion12. In this way, the spacer instrument 10 can be used to align or selectan alignment of the one bone relative to a second bone. For example, thespacer instrument 10 can be used to align a femur relative to a tibia.

In preparing a selected joint for placement of a prosthesis, it isgenerally desirable to maintain or re-obtain a substantially natural orselected articulation and alignment of the bones. The selected alignmentcan be obtained by positioning an instrument to contact a first portionof the bone to achieve or assist in a resection or cutting a secondportion of the bone relative to the first portion. As discussed herein,an alignment tool can be positioned on the bone itself, relative to animplant member, relative to a first cut portion of the bone, or thelike, to assist in or to achieve a resection of a selected secondportion of the bone. It will be understood that the prostheses that arepositioned relative to the resected bone can be a multi-componentprosthesis, a multi-piece prosthesis, or a single piece prosthesis.

A multi-component prosthesis can include a prosthesis that includes twoprosthetic members that are not integrally interconnected, such as twoseparate unicondylar implants. A multi-piece implant can include animplant member that includes more than one piece that is integrallyinterconnected at some point. Finally, a single piece implant caninclude an implant that is substantially formed as a single piece andimplanted relative to the selected joint as a single piece.

Although an exemplary alignment instrument 10 is illustrated, anyappropriate alignment instrument can be provided to align variousportions of a prosthesis or joint. It will be understood that thealignment instrument 10 is merely exemplary of any appropriateinstrument that can be used to achieve an appropriate alignment. Suchother alignment instruments can be reasonably understood by one skilledin the art to achieve a selected result.

A selected method of achieving a result will now be discussed inrelation to FIGS. 3-7. The method can allow aligning a selected implantrelative to another one. Therefore, two implants, or any appropriatenumber of implants, can be aligned relative to one another to achieve aselected result in the anatomy. As discussed above, however, analignment instrument according to various embodiments can be used toalign joint portions or bone portions for positioning a single pieceimplant.

With reference to FIG. 3, a first unicondylar prosthesis 30 can beprovided and a second unicondylar prosthesis 32 can also be provided.The various unicondylar prostheses 30, 32 can be provided to replace aselected portion of the anatomy, such as a medial femoral condyle and alateral femoral condyle. It will be understood that the unicondylarimplants 30, 32 can be any appropriate members, such as the Oxford®Unicompartmental Knee Replacement™ sold by Biomet, Inc., of Warsaw,Ind., USA. The unicondylar implants 30, 32 can include various features,such as a peg 34 that is operable to extend into a selected bore formedin the bone. Further, other fixation mechanisms can be used to fix theunicondylar implants 30, 32 to a selected portion of the anatomy. Theunicondylar implants 30, 32 are generally provided to replace a selectedcondyle of the femur in an anatomy; although it can be selected toprovide implants to replace both articulating condyles of the femur.

With reference to FIG. 4, a femur 40 generally includes a first condyle,which can be a medial or lateral condyle, but is illustrated as a medialcondyle 42 and a second condyle 44, which can also be a medial orlateral condyle, but is illustrated as a lateral condyle. The condyles42, 44 can articulate with a tibial surface or plateau 46 that extendsfrom the tibia 48. It will be understood by those skilled in the artthat generally soft tissues portions are formed on the tibial plateau 46and can also be formed on the condyles 42, 44. Nevertheless, generallywhen the implants 30, 32 are to be positioned in a joint, such as a kneejoint 50, at least parts of the soft tissue portions may be worn away orneed replacement. The condyles 42, 44 may need to be replaced so thatthe implants 30, 32 can replace the femoral condyles. Although thefemoral condyles are replaced, the tibial plateau 46 and the soft tissueassociated therewith can remain substantially intact and can be formedor maintained to articulate with the implants 30, 32. Therefore, theimplants 30, 32 can be implanted to replace the articulating portions ofthe condyles 42, 44 as discussed herein.

Soft tissue 52, such as skin, muscle, adipose tissue, and the likegenerally surrounds the knee joint 50. To obtain access to the condyles42, 44 of the femur 40, an incision 54 is generally made in the softtissue 52. Incision 54 can be any appropriate size to achieve access tothe condyles 42, 44. For example, the incision 54 can be about 1 cm toabout 20 cm, such as about 13-20 cm, in length. Nevertheless, it will beunderstood that the incision 54 can be selected by a user to achieve aselected result.

Once the incision 54 has been formed in the soft tissue 52, access canbe obtained to the condyles 42, 44 to prepare them for implantation ofthe implants 30, 32. It will be understood that any appropriatemechanism and instruments can be used to prepare the condyles 42, 44 toimplant the prostheses 30, 32. For example, as mentioned above, theOxford® Unicompartmental Knee Replacement™ system can be used to preparethe condyles 42, 44 for implantation of the implants 30, 32. Generally,the preparation can include resecting various portions of the condyles42, 44, milling portions of the condyles 42, 44, or any otherappropriate mechanisms or methods. An inferior portion of the condyles,such as portions 42 i and 44 i can be contacted with a saw guide toremove an inferior portion of the condyles 42, 44. Further, variousresection or milling instruments can be used to resect or removeportions of the distal portions of the condyles, such as the distalportion 42 d and 44 d.

Once the various resections on the femur 40 are made, a selected one ofthe implants, such as the first prosthesis member 30, can be positionedrelative to the femur 40 in any appropriate manner. For example, variouscements (e.g., polymethylmethacrylate) can be used to assist in fixingthe prosthesis 30 to the femur 40. Also, various other mechanicalfixation mechanisms can be used to fix the implant 30 relative to thefemur 40. The fixation mechanisms can be selected based upon userpreference, the strength of the anatomy, or any other appropriatereason. Nevertheless, once the implant 30 is positioned relative to thefemur, the alignment tool 10 can be used to insure an appropriatepositioning of the second implant member 32.

For example, the alignment tray 12 can be positioned between the tibialplateau 46 and the first implant portion 30. A first side of thealignment tray 12 a can be formed to touch both the tibial plateau 46and the implant portion 30. The second half of the alignment tray 12 bcan be positioned to touch the tibial plateau 46 and either touch theresected second condyle 44 or the augment or modular member 20 can beselected to achieve contact between the femoral condyle 44 and thetibial plateau 46. It can be understood that the alignment tool 10 canbe used to insure an appropriate alignment between the tibia 48 and thefemur 40. Although it is illustrated that the alignment tool 10 is usedwhile the knee joint is in flexion, it will also be understood thatalignment can be achieved during extension of the joint.

The alignment tool 10 can be positioned between the tibial plateau 46and the implant portion 30 and between the tibial plateau 46 and theresected condyle 44, to assist in obtaining the selected location, suchas the second location. The alignment tool 10 can be used to insure anappropriate alignment of the femur 40 relative to the tibia 48 and alsoinsure an appropriate gap between the femur 40 and the tibia 48. Forexample, as is understood in the art, various soft tissue releases ortensionings may be necessary to insure an appropriate alignment of thefemur 40 with the tibia 48. Therefore, the alignment tool 10 can be usedto insure appropriate alignment of the femur 40 relative to the tibia 48while the implant member 30 is in place and the second condyle 44 is ina resected and prepared condition.

Once the appropriate alignment of the first implant 30 is configuredrelative to the second condyle 44, the second implant portion 32 can beimplanted to complete the procedure. Therefore, the two implant members30, 32 can be implanted relative to the femur 40, one based upon theposition of the other. This can help assure appropriate alignment of thefemur 40 relative to the tibia 48 and also of the second implant member32 to the first implant member 30.

It will be understood that aligning portions of the anatomy to achievean appropriate interaction with multiple implant members relative to theanatomy can also be performed. For example, with reference to FIG. 7,the alignment tool 10 can be positioned relative to the femur 40, whichhas the first condyle 42 resected in an appropriate manner. The firstpart 12 a of the alignment tray 12 can be positioned relative to thesecond condyle 42 to assist in achieving a selected resection of thesecond condyle 44. The appropriate modular member 20 can beinterconnected with the alignment tray 12 to allow for alignment of aresection block 60 on the second condyle 44. The resection block 60 canbe interconnected with the femur 40 in any appropriate manner, such aswith two connecting pins 62 and 64. Once the resection block 60 has beeninterconnected with the femur 40, the alignment tool 10 can bedisengaged from the femur 40. Once the alignment tool 10 is removed, theresection block 60 can be maintained in place to guide a resection ofthe inferior portion of the femur 44 i. In this manner, the inferiorresection of the femur 40, for both the first condyle 42 and the secondcondyle 44, can be substantially aligned with the alignment tool 10.This can allow the two implant members 30, 32 to be positioned on thefemur 40 in a substantially aligned manner to achieve a selected result.It will be understood that the alignment tool 10 can be used to alignany appropriate resection of the femur 40 and using it to align theinferior resection is merely exemplary.

Although the inferior resections can be selected to be matched oraligned with the alignment tool 10, between the first condyle 42 and thesecond condyle 44, the distal resection of the condyles 42, 44 can alsobe substantially matched to one another with the alignment tool 10 orany appropriate alignment tool.

It will be understood that although the alignment tool 10 has beenexemplary described with modular portions, that can be removed, to allowfor achievement of a selected alignment the alignment tool 10 can beused with adjustable portions to achieve similar results. For example,with reference to FIG. 8, once the first condyle 42 of the femur 40 isprepared and the first implant member 30 is positioned relative thereto,an alignment tool 70 can be used to insure an appropriate resection ofthe second condyle 44. The alignment tool 70 can be used to align anyappropriate resection such as the resection of the distal portion 44 dthereof. The alignment tool 70 can include a first foot or contactmember 72 and an adjustable or second contact foot 74. The two feet 72,74 can be interconnected with a connection member 76 that can alsoextend from a handle 78 for manipulation by a user. An adjustmentmechanism 80 can be provided relative to the second foot 74 to move thesecond foot 74 relative to the alignment tool 70, such as relative tothe first foot 72. Any appropriate indication, such as markings 82 onthe adjustment portion 80, can be used to indicate a difference betweenthe first foot 72 and the second foot 74. Therefore, one skilled in theart can determine the amount of the second condyle 44 that needs to beresected to achieve an appropriate alignment with the first implantmember 30 once the two members are implanted relative to one another.

Although the alignment tool 10, or an alignment tool according tovarious embodiments, can be used to align a second resection relative toa first positioned implant member, it will be understood that a secondresection can be aligned in the appropriate portion. For example, afirst and second resection can be aligned relative to one another on asingle bone, such as a femur, including an inferior or a distalresection of a femur. With reference to FIG. 9, an instrument can bepositioned relative to a first portion of the bone, such as the femur.The femur 40 can be resected with a selected instrument, such as a mill.The mill can be any appropriate mill such as the mill provided with theOxford® Unicompartmental Knee Replacement™ from Biomet, Inc. of Warsaw,Ind. The mill can be used to resect a selected portion, such as a distalportion of the femur 42. The mill can be used to mill the distal portionof the femur 42 in any appropriate manner, but may be interconnectedwith a spigot member that is positioned within a bore 98 formed in thedistal end of the femur 42.

An alignment tool 100 can be interconnected with the bore 98 formed inthe distal portion of the femur 42. A manipulation portion can include ahand graspable portion 102 and a rod 104 interconnected with analignment bar or section 106. An adjustment mechanism can include afirst threaded member 108 that can interconnect with the bore 98 formedin the distal portion of the femur 42. The first adjustment mechanism108 can include a stop member 110 so that it is only moved a certaindistance into the bore 98. The adjustment mechanism 108 can beinterconnected with the alignment bar 106 to position a secondadjustment member 112 relative to the second distal condyle 44.

The second adjustment member 112 can include portions similar to theadjustment mechanism 74, discussed above. A plate or member 114 canengage or touch a portion of the condyle 44 and a demarcation or marking116 can be reviewed relative to the alignment member 106 to determine aposition of the condyle 44 relative to the resected distal condyle 42.This can be used to determine a resection amount, position of aresection guide, or any appropriate action. In this way, the secondcondyle 44 can be resected relative to the first condyle 42 in anappropriate manner. It will be understood that the resection can be anyappropriate resection, such as one with a saw, one with a mill, or thelike. Nevertheless, the second resection can be aligned relative to thefirst resection to achieve and alignment of the femur 44. It will beunderstood, however, that any appropriate member or bony member can beresected with the described apparati according to various embodiments.This can allow for positioning of any appropriate prosthesis such as amulti-piece prosthesis, and multi-piece integral prosthesis, or a singlepiece prosthesis.

Nevertheless, the tools used to resect the femur 40 can be movedrelative to the femur 40 so that a single cut need not resect eachportion in a selected plane of the femur 40 to achieve an alignedresection. It is understood the first condyle 42 can be resected at adifferent time than the second condyle 44 with the alignment tool 100.It will be understood that any appropriate single piece implant can beprovided to interconnect with the resected portion of the femur 40 usingthe alignment instrument 100, such as the AGC®, Maxim®, or Asent™ kneesystems provided by Biomet, Inc. of Warsaw, Ind. Exemplary multiplepiece integral prostheses include those disclosed in currently pendingand commonly assigned U.S. patent application Ser. No. 10/901,475 filedJul. 28, 2004, incorporated herein by reference.

Therefore, it will be understood that various methods can be used toachieve an appropriate alignment of two different members in a singlejoint. For example, the second condyle implant 32 can be alignedrelative to the first condyle implant 30, both distally and inferiorly,or medially or laterally, or any other appropriate manner. Further,resection of the second condyle 44 relative to the first condyle 42 canalso be used as an alignment mechanism. Therefore, one skilled in theart will understand that a multi-component implant, such as twounicondylar implants, can be aligned one relative to the other toachieve an appropriate alignment after implantation. Further, it will beunderstand that any appropriate system, prosthesis or the like, such asthat disclosed in concurrently filed U.S. patent application Ser. No.11/444,268, filed on May 31, 2006, now U.S. Pat. No. 7,695,520,incorporated herein by reference, can also be used with the variousembodiments disclosed herein.

Although, one skilled in the art may understand that a singleunicondylar implant can be aligned relative in a joint space, being ableto three dimensionally align one implant relative to another to achievea substantially aligned result for a generally anatomical alignment andpositioning of two implant portions in a single joint, such as amedial/lateral portion, can now be achieved.

1. A method of positioning a prosthesis member on a single bone in ajoint of an anatomy, comprising: positioning an instrument to contact afirst portion of the single bone to assist in a resection of a secondportion of the single bone relative to the first portion of the singlebone; determining a first location of the resection on the secondportion of the single bone; performing the resection at the determinedsecond location on the second portion of the single bone; andpositioning a prosthesis member on the single bone.
 2. The method ofclaim 1, wherein positioning an instrument to contact a first portion ofthe single bone includes contacting the first portion of the single bonedirectly with the instrument.
 3. The method of claim 1, wherein theprosthesis is a single piece prosthesis.
 4. The method of claim 1,wherein the prosthesis is a multi-piece prosthesis.
 5. The method ofclaim 4, further comprising: integrally connecting a first piece and asecond piece of the multi-piece implant.
 6. The method of claim 1,further comprising: obtaining access to the joint by forming an incisionin soft tissue surrounding the joint.
 7. The method of claim 1, whereinpositioning the prosthesis member on the first portion of the singlebone includes positioning a unicondylar implant relative to a singlecondyle on a femur.
 8. The method of claim 1, wherein determining thesecond location of the resection on the second portion of the singlebone includes: contacting a first portion of the single bone with afirst portion of an instrument; and moving an adjustment member of theinstrument relative to the second portion of the single bone while thefirst portion remains contacting the first portion of the single bone.9. The method of claim 1, further comprising: contacting an instrumentwith the first portion of the single bone for determining the secondlocation of the resection of the second portion of the single bone; andpositioning a resection guide relative to the second portion of thesingle bone.
 10. The method of claim 1, further comprising: forming afirst resection of the first portion of the single bone at a first time;and wherein performing the resection at the determined second locationon the second portion of the single bone occurs after forming the firstresection.
 11. A method of positioning a prosthesis member on a singlebone in a joint in an anatomy, comprising: determining a first locationof a first resection on a first portion of the single bone; performingthe first resection at a first time; determining a second location of asecond resection on a second portion of the single bone based on thefirst resection; performing the second resection at a second time afterthe first time; and implanting a prosthesis member relative to at leastone of the first location, the second location, or combinations thereofon the single bone.
 12. The method of claim 11, wherein determining thesecond location of the second resection on the second portion of thesingle bone includes: contacting the resected first portion of thesingle bone with a first portion of an instrument: moving an adjustmentportion of the instrument relative to the second portion of the singlebone; and determining the second location of the second resection basedupon the position of the adjustment portion of the instrument.
 13. Themethod of claim 12, wherein moving the adjustment portion of theinstrument relative to the second portion of the single bone includespositioning a modular member relative to the first portion of theinstrument to determine the second location for the second resection.14. The method of claim 12, wherein moving the adjustment portion of theinstrument includes adjusting the adjustment portion relative to thefirst portion while the first portion is contacting the first portion ofthe single bone.
 15. The method of claim 12, further comprising:positioning a resection guide relative to the second portion of the bonebased upon a position of the adjustment portion of the instrument. 16.The method of claim 15, wherein positioning the resection guide includespositioning a saw guide, positioning a milling guide, positioning anablator, or combinations thereof.
 17. The method of claim 11, furthercomprising: determining an alignment of the single bone relative to asecond bone separate from the single bone; wherein determining thesecond location of the second resection on the second portion of thesingle bone is based on the determined alignment of the single bonerelative to the second bone.
 18. The method of claim 11, wherein theprosthesis is a single one-piece prosthesis.
 19. The method of claim 11,wherein the prosthesis is a multi-piece prosthesis that includesintegrally connecting a first piece and a second piece of themulti-piece implant.
 20. A method of positioning a prosthesis member ona single bone in an anatomy, comprising: forming a first resectedportion on a first portion of the single bone with a first instrument;determining a second location for a second resected portion on a secondportion of the single bone by contacting at least the first resectedportion with a second instrument after forming the first resectedportion; forming the second resected portion at the determined secondlocation; and implanting a prosthesis member relative to the firstlocation, the second location, or combinations thereof on the singlebone.
 21. The method of claim 20, wherein the second resected portion isformed with the first instrument or a third instrument.
 22. The methodof claim 20, wherein determining the second location of the secondresected portion includes: contacting the first resected portion of thesingle bone with a first portion of the second instrument; and moving asecond portion of the second instrument relative to the second portionof the single bone.
 23. The method of claim 22, wherein moving thesecond portion of the second instrument includes positioning a modularmember relative to the second portion of the second instrument todetermine the second location for the second resected portion.
 24. Themethod of claim 22, wherein moving the second portion of the secondinstrument includes adjusting the second portion of the secondinstrument relative to the first portion of the second instrument. 25.The method of claim 20, further comprising: determining an alignment ofthe single bone relative to a second bone; wherein determining thesecond location for the second resected portion on the second portion ofthe single bone includes determining the alignment of the single bonerelative to the second bone.
 26. The method of claim 20, whereinimplanting a prosthesis includes implanting a single piece prosthesisonto the single bone.